1. Field of the Invention
The present invention relates to a wear-resistant alloy of high permeability consisting essentially of Ni, Nb and Fe, a wear-resistant alloy of high permeability comprising Ni, Nb and Fe as main components and at least one subsidiary component selected from the group consisting of Cr, Mo, Ge, Au, Co, V, W, Ta, Cu, Mn, Al, Si, Ti, Zr, Hf, Sn, Sb, Ga, In, Tl, Zn, Cd, rare earth elements, platinum group metals, Be, Ag, Sr, Ba, B, P and S, and methods of producing the same.
2. Description of the Prior Art
Heretofore, magnetic record play-back heads of tape-recorders and the like are operated in A.C. magnetic field, so that magnetic alloys used therefor are required to have high effective permeability in a high frequency magnetic field and a good wear-resistant property because they contact with sliding magnetic tapes. Recently, as wear-resistant magnetic alloys for magnetic heads there have been Sendust which is an Fe--Si--Al series alloy and Mn--Zn ferrite which is an MnO--ZnO--Fe.sub.2 O.sub.3 alloy. However, these alloys have drawbacks in that they are so hard and brittle that they can not be forged or rolled and have to be processed to head cores by laborsome and time-consuming cutting or grinding work, so that the products are very expensive. Though Sendust has a high magnetic flux density, it can not be processed to a thin plate, so that it has a shortcoming of a relatively low effective permeability value in high frequency magnetic field. While ferrite has a high effective permeability, it has a shortcoming of a low saturation magnetic flux density of about 4,000 G. On the other hand, Permalloy, which is an Ni--Fe series alloy, has a high saturation magnetic flux density, however, it has a drawback of a low effective permeability. Though Permalloy can be mass produced easily by forging, rolling or punching, it has also a great drawback of low wear-resistance.
The inventors had previously found out that an Ni--Fe--Nb series alloy and an Ni--Fe--Ta series alloy are easy to be worked or processed by forging and have high hardness and permeability so that they are suited well to magnetic alloys for magnetic heads, and filed patent applications therefor which matured to U.S. Pat. Nos. 3,743,550 and 3,785,880.
Afterwards, the inventors have produced thin plates of the Ni--Fe--Nb series and Ni--Fe--Ta series alloys for magnetic alloys for magnetic heads. As a result, the inventors have found out a great problem that abrasion or wear-resistant property of a magnetic head made of the thin plate caused by sliding contact of a magnetic tape thereon varies noticeably depending on the manner of working and heat treatment in the process of producing the thin plate, and that the wear-resistant property of the thin plate often shows a considerably inferior value depending on the manner of working and heat treatment.